The first woman to act as governor was Carolyn B. Shelton, who served as "acting governor" of Oregon for one weekend – 9 a.m. Saturday, February 27, through 10 a.m. Monday, March 1, 1909. The outgoing governor, George Earle Chamberlain, had been elected to the Senate and had to leave for Washington, D.C., before his term was over, and the incoming governor, Frank W. Benson, had gotten sick and couldn't assume office early. Chamberlain left Shelton, his "Chief of Staff," in charge for the weekend.[1] Ironically enough, it would be another three and a half years before women would be allowed to vote in Oregon.[2] (As a side note, Chamberlain and Shelton married each other 17 years later.[3])

The first acting governor to be entrusted with substantial duties while in office was Soledad Chávez de Chacón, who held the powers and duties of Governor of New Mexico for 2 weeks in 1924 while Governor James F. Hinkle attended the Democratic Convention in New York. Lieutenant Governor Jose A. Baca had died unexpectedly in May, so Chacón, the Secretary of State, filled the position. Chacón said she believed that her 1924 elevation was the first time in the U.S. that a woman had been called on to assume the responsibilities of governor.[4]

The first woman to assume office as governor pursuant to an election was Nellie Tayloe Ross of Wyoming (widow of late Governor William B. Ross, served January 1923 to October 1924), who was elected on November 4, 1924, and sworn in on January 5, 1925.[5] Wyoming was the first state to provide women's suffrage[6] after New Jersey had abolished it in 1807. Elected on November 3, 1924, and sworn in on January 20, 1925, was Miriam A. Ferguson of Texas, whose husband, Governor James Edward Ferguson, had previously held the office but been impeached and removed from office in 1917.[7] The first female governor elected without being the wife or widow of a past state governor was Ella T. Grasso of Connecticut, elected in 1974 and sworn in on January 8, 1975.[8]

Connecticut and Arizona are the only two states to have elected female governors from both major parties. New Hampshire has also had female governors from both parties, but Republican Vesta M. Roy only served in the acting capacity for a short time. Arizona was the first state where a woman followed another woman as governor (they were from different parties). Arizona also has had the most female governors with a total of four, and is the first state to have three women in a row serve as governor.

As Secretary of State, she succeeded to the office when Governor John Kitzhaber resigned and won the 2016 special election to complete the term. Second woman to serve as Governor of Oregon and first openly bisexual United States governor.

First (and only to date) woman to serve as Governor of South Carolina. First non-white Governor of South Carolina. First female Indian American (and Asian American) governor. Also (as of January 2015), the youngest current governor.

Wife of Governor George Wallace (1963–1967, 1971–1979, & 1983–1987). First (and only to date) woman to serve as Governor of Alabama. First female governor elected from the Deep South. First (and only to date) female governor to die in office.

First female governor not a wife or widow of a previous governor. First woman to serve as Governor of Connecticut. First woman governor in the United States to be elected to two consecutive terms, and the first to resign (terminal ovarian cancer).

First Republican woman to serve as Governor of Arizona. First woman to be elected Governor in Arizona. As Secretary of State, she had succeeded Fife Symington following his resignation, and was elected in her own right in 1998.

First woman to be elected to two terms as Governor of Arizona. Third woman to serve as governor overall. Resigned to become Secretary of Homeland Security in the Obama Administration. First woman to immediately succeed another woman as governor.

First (and only to date) woman to serve as Governor of Alaska (also Alaska's youngest Governor). First female Governor of any state to appear on a major party presidential ticket, as the Republican candidate for vice president in 2008. First elected governor to give birth while in office.

As Secretary of State, she succeeded to the office when Governor Janet Napolitano resigned. Third consecutive woman to serve as Governor of Arizona, and the fourth overall, a national record. Was elected in her own right in 2010.

First woman to serve as Governor of Puerto Rico. Formerly Puerto Rico's secretary of State and mayor of San Juan.

Popular Democratic Party: While it generally aligns with the U.S. Democratic Party, it is not a formal branch or affiliate, and is characterized in Puerto Rican politics mainly by support for continued status as a U.S. commonwealth, contrasting other major parties advocating statehood and independence.